Which of the following men developed the cold war method of negotiation known as brinksmanship?
a. john foster dulles
b. john f. kennedy
c. harry truman
d. george kennan

 A. John Foster Dulles

According to the idea of brinkmanship, a nation can prevent war by threatening massive retaliation against any hostile act by an enemy nation.

Context/detail:

John Foster Dulles was Secretary of State under President Eisenhower.  He held the office from 1953 to 1959.  He wanted a change from what had been the "containment policy" which the US had followed during the Truman Administration, as recommended then by American diplomat George F. Kennan.   Dulles felt the containment approach put the United States in a weak position, because it only was reactive, trying to contain  communist aggression when it occurred.

Dulles sought to push America's policy in a more active direction; some have labeled his approach "brinkmanship."  In an article in LIFE magazine in 1956, Dulles said, "The ability to get to the verge without getting into the war is the necessary art."  He wasn't afraid to threaten massive retaliation against communist enemy countries as a way of intimidating them.

to act quickly in times of danger to the united states

because you have to act quickly if you want to live/survive.

the correct answer is 50.